I've only just got this car. EA 89 Fairmont.. LPG/Petrol.
I've been starting it cold using petrol, then flicking it over to LPG once warmed up.. but it is idling like a dog! It's like it has a power surge.. idles right down to about 100 rpm then revs up to 1000 again.. then back down again etc...
Checked the petrol inlet etc and it is filthy, full of dust and crap .. and i don't think the last guy ever used the petrol! would the petrol be off? and does it sound like a carby blockage? if so, what's the best way to rectify this.. without having to pull the carby to bits???? it has about 3/4s of a tank of petrol... do i have to drain that all out? any thoughts would be fantastic! love the car.. but this is a real worry!

the petrol could well be off and the injectors are gummed up alittle
how does she run on petrol? is it only the idle that is ordinary?
Does it flare and hunt for idle when you start it on LPG?
LPG uses a differnt heat range plug so it is quite possible he has the timing set for LPG and using LPG range sparkplugs

EA are not a carby but CFI or MPI, but as you think you are looking at the carby yours is CFI.. So it is actually a fuel injected car

thanks for that.. i know absolutely nothing about these...
it is doggy idling on petrol or lpg, perfect when in drive.. seems to just be in neutral.
drives beautifully.

i just moved it out of the driveway a few mins ago, and it was on petrol... hesitated, blew black smoke, then decided to drive forward....
it seems to only have started since i'm starting it on petrol... as starting on lpg in the mornings was a bit of a process... turned over and over before firing etc...